Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

Lasrick sends this report from Nature News:
"The devastating 2011 earthquake and tsunami in Japan shocked researchers who did not expect that the seismic fault involved could release so much energy. Now the world's deepest-drilling oceanographic ship has been able to pin down the odd geology that made this disaster so horrific. The fault turns out to be unusually thin and weak, the researchers report in Science this week1–3. The results will help to pin down whether other offshore faults around the world are capable of triggering the same scale of disaster. ... The coring revealed a very thin clay layer, about 5 meters thick, separating the two sliding tectonic plates (abstract). 'That’s just weird,' says Emily Brodsky of the University of California, Santa Cruz (UCSC), who is an author on all three Science papers this week. 'Usually it’s tens of meters or more.' Lab tests confirmed that this wet clay layer is extremely slippery, and gets even more so under stress (abstract). As sliding creates friction and heat, water in the clay gets pressurized and pushes up against the impermeable rock around it. That 'jacks open the fault” says Brodsky, allowing it to slip even more. The temperature sensors found that more than a year after the quake, the fault was still up to 0.31 C warmer than its surroundings (abstract). From this they could extrapolate how much heat was generated from friction during the sliding event. Their calculations confirmed the very low friction of the 5-meter-thick clay layer."

Statistically, five meters really isn't much different from ten meters, or twenty meters, or even thirty meters. It's only when you get to about 80 meters or so that we see a statistically-significant deviation from the standard probability distributions.

And you know this because you have the distribution of thicknesses and computed the standard deviation. Right?

let me get this straight, you don't think there is japanese porn of soldier women getting bukkake, or of soldiers giving a woman bukkake? you don't know much about Japanese porn, do you? if it can be conceived by anyone's mind, there is a genre of Japanese porn for it.

Yeah, let's make it build up more pressure before release - that'll work juuuuust fine!:)

In 100 years or so, there will probably be even better technology available to more effectively add friction to the fault line, or transfer the kinetic energy from the release, so the fault begins to form in some safer place.

In 100 years or so, there will probably be even better technology available to more effectively add friction to the fault line, or transfer the kinetic energy from the release, so the fault begins to form in some safer place.

Or it'll form in some less safe place. Or somewhere no better and no worse (but without the century-worth of investment.

In fact, your scheme wouldn't work. The stress would just move up to the top (or bottom) of your re-bar reinforced layer and start slipping there. You'd have to chil

Japan seems to have made most of their buildings pretty earthquake safe already. Fixing the earth seems like a less efficient step even assuming we were sure we weren't going to make it worse. Japan regularly experiences and ignores earthquakes which would cause a lot of damage elsewhere.

That's not to say we should discount any possibility of fixing the plates to suit us. California for example has been taking some cues from Japan in earthquake proofing, but hasn't done nearly as much, and will be fac

Don't forget that they also design their cities with firebreaks in mind, entire sections of cities are designed to stop fires from running wild throughout even with the collapse of buildings and NG ruptures. It's not fool proof but if you only lose 1/10 of a city to fire instead of the entire thing because you can't get emergency services rolling, or a lack of water it sure does help. Wish I could find the articles on it from a few years ago, very interesting, I'm pretty sure Natgo has also done a few sho

heavy water is not even radioactive, in concentrations of thousandth or less it has no observable effects. the concentration in a plant or animal becomes high, several percent and up, it does start interfering with enzymes and cell division. but those studies that poison creatures had to use tens (not tenths) of percent

Not all. Some actually were a bit smarter and there is this one small village that had flood gates high enough because the Major looked at historic flood markers, and then pushed through what was actually needed. This just means that people in general are stupid and blind and only see what they want to see. The few exceptions demonstrate that the facts are actually there, but are getting ignored. However I see no indication that Japanese women are smarter then the "Herbivores". In fact, they seem to fit rig

Geologists are typically extremely competent fellows with no political agenda. The field is just too slow and usually non-spectacular for that. I suggest you read the articles instead of calling them incompetent, however indirectly you are doing it.

As to speed, do you know how long the review process in a reputable Journal can take? The delay is just average here.

Most of the info is in the Nature article, the paper, though probably funded by the taxpayes, is securely behind the AAAS paywall. Maybe Congress, if it had any balls, would make it illegal to publish publically funded research behind a paywall, but I digress.

The message here seems to be that there were really two geologic events on the subduction zone of Japan's northern coast in March 2011. The first was an an ordinary subduction quake at modest depth in the plane of the Benioff Zone, a thrust event, b